<template>
  <div>
    父组件--{{ num }}
    <!-- <Son v-model="num" /> -->
    <Son
      :aa="num"
      :bb="num2"
      @update:aa="val => num = val"
      @update:bb="val => num2 = val"
    />
    <Son
      :aa.sync="num"
      :bb.sync="num2"
    />
  </div>
</template>

<script>
import Son from './Son.vue'
export default {
  components: {
    Son
  },
  data() {
    return {
      num: 10,
      num2: 20
    }
  }
}
</script>
